Producing isoprene.



UNITED s'ra'rns ran'r anion FRANZ WEBEL, 0F LUDWIGSHAFEN-ON-THE-BHINE,GERMANY, ASSIG-NOR TO BADI SGHE' ANILIN & SODA FABRIK, 0FLUDWIGSHAFEN-ON-THE-RHINE, GERMANY, A GQB'PORATION.

TRODUCING ISOPRENE.

mosaics.

Specification of Letters Patent. Patented Dec. 3t), 1913. No Drawing.

Application filed June 30. 1913. Serial No. 776,550.

To all whom it may concern:

' Be it known that I, FRANZ WEBEL, a citizen of the German Empire,residing at Ludwigshafen-on-the-Rhine, Germany, have invented new anduseful Improvements in Producing Isoprene, of which the following is a;specification.

I have found that I can obtain isoprene from isopropyl-acetylene byheating the latter with a contact substance consistln of or containingalumina, preferably un er reduced pressure. l

The following example will serve to illustrate further the nature of myinvention, which, however, is not confined to this example: Lumps ofalumina are introduced into; a tube connected at one end with a droppingfunnel and at'the other-end with a re ceiver cooled to about -80 C. andwhich also is connected to a vacuum pump. The apparatus is evacuated andthe tube heated to about 400 C., isopropyl-acetylene of boiling point 28C. is .then allowed to drop into the 'tube in such a-manner that apressure of about from 40 to millimeters is maintained. The isoprenewhich condenses in the receiver can be freed from any small quantitiesof isopropyl-acetylene by shaking with ammoniacal cuprous chloridsolution.

Now what I claim is 1. The process of producing isoprcne by treatingisopropyl-acetylene with a contact substance containing alumina at araised temperature.

2. The process of producing isoprene by treating isopropyl acetylenewith a contact substance containing alumina at a raised.

temperature and under reduced pressure.

3. The process of producing isoprene by passing vaporizedisopropyl-acetylene over a contact substance containing alumina at atemperature of about 400 C. and at a pressure of about 40 to 50millimeters.

In testimony whereof I have hereunto set- Witnesses: J. Anne. LLOYD.

JOSEPH PF IFFER.

